1. Field of the Invention
This invention relates generally to indicating devices and more specifically to visual indicating devices to assist a vehicle driver to align his vehicle with a trailer.
2. Description of the Prior Art
Cars and trailers are often coupled with a ball and socket hitch. The ball is usually placed at the rear end of the vehicle and the socket is placed at the front end of the trailer. The hitch is placed on the frame below the body of the vehicle for reasons of stability between the vehicle and trailer.
In order to correctly hitch the socket and ball elements of the hitch, the two members must be properly aligned with each other. Both the car and the trailer are much too heavy for a person to physically pull them together so that the hitch members are properly aligned.
The usual method is to back up the car so the hitch members are aligned. The problem of alignment is complicated by the fact that the ball member is not visible from the driver's seat so the driver needs an assistant's help to tell him which way to steer or he must stop and get out of the car a number of times and spot check his position. Even an experienced driver must get out of his car to spot check to see if he is correctly approaching the socket member attached to the trailer. The problem is further complicated because the trailer socket member becomes blocked from view by the rear end of the car when the car approaches the trailer so the final alignment of the two hitch members becomes even more difficult because neither hitch member is visible.
Alignment devices have been devised so they can attach to the car and trailer. The devices often comprise rod-like members vertically extending upward from the ball member and socket member of the hitch. The top sections of the rod often have sighting devices such as a colored ball which are aligned togehter. One such device is disclosed in U.S. Pat. No. 3,818,599 issued to Tague on June 25, 1974. Sometimes the sighting element of one socket member is made to fit between a pair of balls extending from the ball member of the hitch. One such device is disclosed in U.S. Pat. No. 3,765,703 issued to Voelkerding et al on Oct. 16, 1973. Other arrangements such as a ball fitting within a groove have been used. One such example is disclosed in U.S. Pat. No. 3,159,917 issued to Whitehead on Dec. 8, 1964.
Sometimes a problem between hitching a vehicle to a trailer is that often the trailer and car are on a side of a hill so that the rods are displaced from the vertical and do not adequately align the socket and ball member of the hitch.
U.S. Pat. No. 3,015,162 to Bohnet issued Jan. 2, 1962, discloses a vertical rod alignment device wherein the vertical rod above the ball member maintains the vertical position.
Different mountings have been used to mount the vertical rods to the socket and ball members of the hitch. Magnetic mounts have been disclosed in U.S. Pat. No. 3,818,599 issued to Tague on June 25, 1974, and U.S. Pat. No. 3,966,231 to Metzler issued on June 29, 1976.
Rubber fittings which fit over a ball and the rubber ball which fits within the socket also have rods mounted to the hitch members. One such device is disclosed in U.S. Pat. No. 4,012,056 issued to Christensen on Mar. 15, 1977.
Resilient spring mounts on a ball on a second resilient coil wedged onto the socket member are disclosed in U.S. Pat. No. 3,867,898 issued to Lakamp on Feb. 25, 1975.
Problems arise with the use of vertical rod alignment devices when vehicles other than cars are used. Nowadays, many people drive vans, pick-up trucks, and other vehicles which may not have a rear window. If the rear window is on the vehicle, often it is positioned much higher than a car rear window and also may be only a small opening in a rear end door. Conventional alignment devices are not suitable for use with these vehicles. The sighting elements such as a ball are often placed on rods which are too short and are not visible through the rear window. Sometimes the sighting element is blocked by an opaque rear end door. At other times, a driver's view through the rear window may be blocked by luggage packed into the vehicle. A guide device is needed wherein the alignment device is visible from the side of the vehicle.
An inexpensive guide device is needed which has two similar components, each component being mountable to either engageable member of the hitch. A mount for the components is needed so that the rod members of each component are adaptable for either vertical or horizontal mounting. A horizontally disposed rod is needed to allow the sighting elements to be viewed from the side window when the rear view is blocked by luggage or if the certain vehicle does not have a rear window. Also, the horizontally disposed rods can be used on a vehicle and trailer where the vehicle must go uphill or downhill to be aligned with the trailer.